Omegas are inviting. Warm. The heart of pack life. Tsuna never believed he'd be any of those things. (Omega Tsuna, warm and wonderful but entirely unaware of it, unwittingly draws others to him and inspires unwavering loyalty.) No Mafia. Tsuna's "Family" is just his patchwork pack of similarly damaged children. Lots of platonic pack feels and bonding. Endgame Tsuna/Hibari.

Xanxus doesn't put it all together at first. He's too focused on protecting his family from the spawn of Iemitsu. But then Squallo saves the Rain brat, and Xanxus takes a second look.

Tsuna learned young that he was not his parents priority. So he never said anything about the itch under his skin, about the way he sometimes felt his body burn from the inside or how the only time he felt calm was when blood ran like rivulets down his skin. [Or the one where Tsuna finds a family for himself and subsequently starts taking over the world (by accident)]